Speaker
Description
The worldwide LIGO-Virgo-KAGRA (LVK) network of gravitational-wave (GW) detectors continues to increase in sensitivity, thus increasing the quantity and quality of the detected GW signals from compact binary coalescences. These signals allow us to perform ever-more sensitive tests of general relativity (GR) in the dynamical and strong-field regime of gravity. We present the results of a suite of tests of GR using the binary signals included in the fourth GW Transient Catalog (GWTC-4.0), i.e., up to and including the first part of the fourth observing run of the detectors (O4a). We restrict our analysis to the 91 confident signals, that were measured by at least two detectors, and have false alarm rates ≤ 10^−3 yr^−1. These include 42 events from O4a. We discuss the results and their implications for GR and alternatives/extensions, as well as the challenges and state of the field going forward. Based on: [arXiv:2603.19019] GWTC-4.0: Tests of General Relativity. I. Overview and General Tests [arXiv:2603.19020] GWTC-4.0: Tests of General Relativity. II. Parameterized Tests [arXiv:2603.19021] GWTC-4.0: Tests of General Relativity. III. Tests of the Remnants. This talk is on behalf of the LVK Collaboration